The asylum seekers have been stranded on the Nosco Victory for seven days, which plucked them from the sea after their boat sank.

Singapore authorities have refused to allow the ship to enter its harbor, saying those rescued "do not appear to be persons eligible to enter Singapore."

Vivian Tan, a spokesperson for the UN High Commissioner for Refugees, said the group should receive ''any medical or other urgent assistance as needed and for the process to begin of determining if they are in need of international protection''.

"We're appealing to the authorities in Singapore to look at this on purely humanitarian grounds," Ms Tan told ABC Radio Australia's Connect Asia program.

"These people have survived a boat accident, they've seen other people drown, they were in the water for some time . . . so they are probably not in very good condition."